This invention relates to a power device for driving an auxiliary equipment for an internal combustion engine, and more particularly to a power device for driving an auxiliary equipment which is arranged on the internal combustion engine and feeds driving power from a generator driven by the internal combustion engine to a motor for driving a fuel pump for feeding fuel to an injector and an actuator for driving an exhaust characteristic adjusting valve for adjusting characteristics of an exhaust system.
Recently, an auxiliary equipment of the electric type has been generally used for the purpose of improving performance of an internal combustion engine. Such an auxiliary equipment is adapted to be attached to an internal combustion engine to operate the engine. Typically, an internal combustion engine tends to incorporate a fuel injection device acting as a fuel feed means therein. Such a fuel injection device generally requires an injector of the electric type, a fuel pump for feeding fuel to the injector and a pump motor (electric motor) for driving the fuel pump. For example, Japanese Patent Application Laid-Open Publication No. 170541/1988, Japanese Patent Application Laid-Open Publication No. 259127/1988 and U.S. Pat. No. 5,161,496 each disclose a fuel injection device which includes a fuel feed means comprising an injector and a fuel pump for feeding the injector with fuel.
Also, an improvement in performance of an internal combustion engine at a high rotation speed of the engine has been carried out by arranging an exhaust valve for adjusting characteristics (resonance frequency) of an exhaust system of the engine. The exhaust valve is adjusted during driving of the engine at a high rotation speed to cause a standing wave to be generated in the exhaust system, resulting in exhaust and air intake taking place with increased efficiency. However, this requires to arrange an actuator of the electric type for actuating the exhaust valve. For example, Japanese Patent Application Laid-Open Publication No. 4819/1986 and Japanese Patent Application Laid-Open Publication No. 100222/1988 each disclose use of an exhaust characteristic adjusting valve.
Also, a gasoline engine requires an ignition device, as well as an electronic device such as a microcomputer, CPU or the like for controlling an ignition timing of the engine and an injection timing of fuel of the engine.
Conventionally, the fuel injection device has been exclusively used for an internal combustion engine for a vehicle mounted with a battery, therefore, it is generally constructed so as to be operated while using the battery as a power supply therefor. In addition, it is now desired that the fuel injection device is used for an internal combustion engine for a vehicle mounted with no battery such as an outboard boat, a snow mobile or the like. However, this requires to drive an injector or an actuator using a magneto driven by the engine as a power supply.
Also, even when the vehicle is mounted with a battery, it is often required to drive the fuel injection device by means of an output of the magneto and start the engine through a man-powered starting device. For example, a vehicle used in a cold district such as a snow mobile or the like requires man-powered starting operation because the battery is unserviceable in a cold season, thus, use of the fuel injection device causes a magneto to be required for driving it. Also, when such a failure in operation of an internal combustion engine as encountered with a snow mobile or an outboard boat causes an operator to meet with any danger, a starting device is preferably used in combination with a battery. Further, even when the fuel injection device is driven by means of a battery, it is desirably driven by a magneto when the batter is unserviceable.
In order to permit the fuel injection device to be serviceable without using any battery in view of the foregoing, the prior art proposes a construction wherein a generating coil for driving a pump is provided in a magneto mounted on an internal combustion engine to drive a pump motor, as disclosed in U.S. Pat. No. 3,502,895 and Japanese Patent Application Laid-Open Publication No. 63929/1992.
Further, U.S. Pat. No. 5,161,496 and Japanese Patent Application Laid-Open Publication No. 259127/1988 each propose application of a fuel injection device to an internal combustion engine for a vehicle mounted with no battery. The application is accomplished by using a fuel pump of the mechanical type requiring no electricity and incorporating a generating coil for lighting rather than a generating coil for ignition in a generator for the purpose of controlling the fuel injection device.
Moreover, in view of the fact that only a half-cycle output of an ignition power coil provided in a magneto is used for feeding of ignition energy, it is attempted that the remaining half-cycle output of the ignition power coil which is not utilized for feeding of ignition energy is used for a DC power supply, of which an output is used for driving an injector or an electronic device such as a microcomputer or the like.
In addition, it is considered that in order to provide an exhaust characteristic adjusting valve on an engine for a vehicle mounted with no battery, a generating coil for driving the valve is arranged in a magneto mounted on the engine, to thereby permit the generating coil to feed an actuator for driving the valve with electric power.
Unfortunately, the magneto is required to produce electric power for lighting as well, so that the magneto is conventionally provided therein with an ignition power coil and a generating coil for driving a pump. Thus, it is substantially impossible to further provide the above-described valve-driving generating coil in the magneto constructed in a conventional manner. Arrangement of the valve-driving generating coil in the magneto causes it to be large-sized, leading to large-sizing of the engine and to be increased in manufacturing cost.